Dissemination

White Papers

Quality of Service in Cognitive Radio Systems: System architecture options and detailed functions

ABSTRACT

In order to elaborate a framework for Cognitive Radio Systems making opportunistic use of radio spectrum like e.g. TV White Spaces, promising scenarios have to be identified first. The corresponding use cases must be studied in detail too. In the QoSMOS project three scenarios called ‘Cellular extension in White Spaces’, ‘Cognitive Femtocell’ and ‘Cognitive ad-hoc network’ have been selected as the most promising ones. The requirements which have to be fullfilled by the intrinsic system functions are then to be derived from the challenges encountered in the scenarios. These concern mostly stakeholders’ cost, system operation and performance as well as architecture and complexity. With the aim of a flexible architecture design for the QoSMOS system, the system functions needed to fulfil the requirements are illustrated in the overall system reference model elaborated. The combinations of centralised or distributed topologies for Resource Control with centralised, distributed or local topologies for Spectrum Sensing are used to characterise the realisation of the cognitive functions in the scenarios selected. System architecture options are presented for the various topologies’ combinations when mapped to the relevant network elements. Detailing the information flows over the network domains for ‘Spectrum Portfolio Management’, ‘Resource Control and Incumbent Protection’ as well as ‘Mobility Management’ shows the flexibility of the system architecture design achieved.

Business Opportunities and Scenarios for Cognitive Radio Systems

ABSTRACT

The European Commission project QoSMOS specifies and develops a cognitive radio system which will allow opportunistic use of radio spectrum for mobile users as well as providing managed Quality of Service (QoS). If opportunistic wireless access is to be a real alternative to current licence-based technology it must be able to provide at least as good a user experience. Some of the most interesting business opportunities are the access to the wireless market for new entrants and well as benefits for current wireless operators. Some examples are easier access to new markets, capacity enhancements, spectrum sharing, spectrum trading, cost and performance gains in existing networks and new services.

If a cognitive radio system is to be attractive for actors in the wireless industry, it has to provide significant benefits. Consequently, the QoSMOS project has defined several criteria to find feasible deployment scenarios for cognitive radio systems. These criteria address both technical and commercial factors. The resulting promising scenarios are cognitive femtocells, cellular extension in whitespaces (including rural broadband) and cognitive ad-hoc networks. All of these could provide a benefit, either for new entrants, or for existing wireless operators and fixed broadband operators. Some initial business case definitions have been set up.

Spectrum trading is an important tool to increase overall spectrum utilization and to open up opportunities for businesses to get access to desired spectrum. An ecosystem for spectrum trading consisting of spectrum traders, spectrum brokers, spectrum databases and a spectrum regulator has been defined. In addition, a wireless sensor network may be implemented to provide more detailed information about the real-time spectrum status. Fair trading is dependent on well-defined trading metrics which are quantifiable measures of the performance of the trading market. Recommended high levels metrics are market viability, channel quality, spectrum utilization and social welfare.

This white paper explains the business environment in which cognitive radio may exist and benefit in the future.

Cognitive Context Acquisition

ABSTRACT

This white paper presents an overview of cognitive context acquisition mechanisms which are under consideration in the European Union (EU) FP7 Integrated Project (IP) called QoSMOS. Its main focus is to present two context-awareness approaches: spectrum sensing and access to spectrum databases. Spectrum sensing is considered one of the principal enabling technologies for future opportunistic network in last decade. However, current regulatory trends (for instance Ofcom in UK, and FCC in USA) are more in the favour of spectrum database approach in the TV white space context. This white paper highlights the sensing algorithms and the detailed BT1 whitespace estimator, considered in QoSMOS. The main findings are summarised in a conclusion section.

Cognitive Radio Resource Management

ABSTRACT

This white paper presents an overview of cognitive radio resource management studied in the European Union (EU) FP7 Integrated Project (IP) called QoSMOS.

The work reported includes the design of a Cognitive Manager for Resource Management (CM-RM) to manage an opportunistic use of the spectrum whitespaces, tools for design and performance evaluation for cognitive radio networks (CRNs), and resource management solutions for CRNs in all the three main target scenarios of QoSMOS, i.e., cognitive femtocells, cellular extension in the TV white spaces, and cognitive ad hoc networks.

Flexible Multicarrier PHY Design for Opportunistic Spectrum Access

ABSTRACT

Opportunistic use of White Spaces (WS) has opened up a whole new paradigm in research on cognitive radio (CR). One of the issues addressed by the QoSMOSproject is the design of a flexible and efficient physical layer (PHY) for CR systems. To this aim, different modulation techniques are being investigated and are presented in this paper. They fulfil the low out of band leakage and spectral efficiency requirements of a CR operating in fragmented WS. The design of reconfigurable and flexible radio-frequency (RF) front-end is also introduced, since its performance is tightly linked to these parameters and to the implementation feasibility and constraints. Emphasis is put on benchmarking the performance of the proposed schemes over classical approaches.

Joint RAS White Paper on Spectrum Sharing

ABSTRACT:

Edited by QoSMOS, this WP presents some results and discussion on spectrum sharing. It gives results from several FP7 projects in the RAS cluster and discusses interference mitigation and what remains to be done to bring spectrum sharing to market. Starting with the rationale for sharing, the paper goes on to describe the good work that has been done, especially in the development and demonstration of enabling technologies. Perhaps the biggest remaining challenges are the adoption of uniform regulation across Europe and the building of confidence that harmful interference will not be an issue.